From: Waiman Long <longman@xxxxxxxxxx> Subject: mm/memcg: relocate mod_objcg_mlstate(), get_obj_stock() and put_obj_stock() All the calls to mod_objcg_mlstate(), get_obj_stock() and put_obj_stock() are done by functions defined within the same "#ifdef CONFIG_MEMCG_KMEM" compilation block. When CONFIG_MEMCG_KMEM isn't defined, the following compilation warnings will be issued [1] and [2]. mm/memcontrol.c:785:20: warning: unused function 'mod_objcg_mlstate' mm/memcontrol.c:2113:33: warning: unused function 'get_obj_stock' Fix these warning by moving those functions to under the same CONFIG_MEMCG_KMEM compilation block. There is no functional change. [1] https://lore.kernel.org/lkml/202111272014.WOYNLUV6-lkp@xxxxxxxxx/ [2] https://lore.kernel.org/lkml/202111280551.LXsWYt1T-lkp@xxxxxxxxx/ Link: https://lkml.kernel.org/r/20211129161140.306488-1-longman@xxxxxxxxxx Fixes: 559271146efc ("mm/memcg: optimize user context object stock access") Fixes: 68ac5b3c8db2 ("mm/memcg: cache vmstat data in percpu memcg_stock_pcp") Signed-off-by: Waiman Long <longman@xxxxxxxxxx> Reported-by: kernel test robot <lkp@xxxxxxxxx> Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx> Acked-by: Roman Gushchin <guro@xxxxxx> Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memcontrol.c | 106 +++++++++++++++++++++++----------------------- 1 file changed, 53 insertions(+), 53 deletions(-) --- a/mm/memcontrol.c~mm-memcg-relocate-mod_objcg_mlstate-get_obj_stock-and-put_obj_stock +++ a/mm/memcontrol.c @@ -776,24 +776,6 @@ void __mod_lruvec_kmem_state(void *p, en rcu_read_unlock(); } -/* - * mod_objcg_mlstate() may be called with irq enabled, so - * mod_memcg_lruvec_state() should be used. - */ -static inline void mod_objcg_mlstate(struct obj_cgroup *objcg, - struct pglist_data *pgdat, - enum node_stat_item idx, int nr) -{ - struct mem_cgroup *memcg; - struct lruvec *lruvec; - - rcu_read_lock(); - memcg = obj_cgroup_memcg(objcg); - lruvec = mem_cgroup_lruvec(memcg, pgdat); - mod_memcg_lruvec_state(lruvec, idx, nr); - rcu_read_unlock(); -} - /** * __count_memcg_events - account VM events in a cgroup * @memcg: the memory cgroup @@ -2137,41 +2119,6 @@ static bool obj_stock_flush_required(str } #endif -/* - * Most kmem_cache_alloc() calls are from user context. The irq disable/enable - * sequence used in this case to access content from object stock is slow. - * To optimize for user context access, there are now two object stocks for - * task context and interrupt context access respectively. - * - * The task context object stock can be accessed by disabling preemption only - * which is cheap in non-preempt kernel. The interrupt context object stock - * can only be accessed after disabling interrupt. User context code can - * access interrupt object stock, but not vice versa. - */ -static inline struct obj_stock *get_obj_stock(unsigned long *pflags) -{ - struct memcg_stock_pcp *stock; - - if (likely(in_task())) { - *pflags = 0UL; - preempt_disable(); - stock = this_cpu_ptr(&memcg_stock); - return &stock->task_obj; - } - - local_irq_save(*pflags); - stock = this_cpu_ptr(&memcg_stock); - return &stock->irq_obj; -} - -static inline void put_obj_stock(unsigned long flags) -{ - if (likely(in_task())) - preempt_enable(); - else - local_irq_restore(flags); -} - /** * consume_stock: Try to consume stocked charge on this cpu. * @memcg: memcg to consume from. @@ -2816,6 +2763,59 @@ retry: */ #define OBJCGS_CLEAR_MASK (__GFP_DMA | __GFP_RECLAIMABLE | __GFP_ACCOUNT) +/* + * Most kmem_cache_alloc() calls are from user context. The irq disable/enable + * sequence used in this case to access content from object stock is slow. + * To optimize for user context access, there are now two object stocks for + * task context and interrupt context access respectively. + * + * The task context object stock can be accessed by disabling preemption only + * which is cheap in non-preempt kernel. The interrupt context object stock + * can only be accessed after disabling interrupt. User context code can + * access interrupt object stock, but not vice versa. + */ +static inline struct obj_stock *get_obj_stock(unsigned long *pflags) +{ + struct memcg_stock_pcp *stock; + + if (likely(in_task())) { + *pflags = 0UL; + preempt_disable(); + stock = this_cpu_ptr(&memcg_stock); + return &stock->task_obj; + } + + local_irq_save(*pflags); + stock = this_cpu_ptr(&memcg_stock); + return &stock->irq_obj; +} + +static inline void put_obj_stock(unsigned long flags) +{ + if (likely(in_task())) + preempt_enable(); + else + local_irq_restore(flags); +} + +/* + * mod_objcg_mlstate() may be called with irq enabled, so + * mod_memcg_lruvec_state() should be used. + */ +static inline void mod_objcg_mlstate(struct obj_cgroup *objcg, + struct pglist_data *pgdat, + enum node_stat_item idx, int nr) +{ + struct mem_cgroup *memcg; + struct lruvec *lruvec; + + rcu_read_lock(); + memcg = obj_cgroup_memcg(objcg); + lruvec = mem_cgroup_lruvec(memcg, pgdat); + mod_memcg_lruvec_state(lruvec, idx, nr); + rcu_read_unlock(); +} + int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s, gfp_t gfp, bool new_page) { _
